Agilent Technologies TV70 Navigator 969-8970, User Manual

Page: 165 / 182

Technical Information
RS 232/RS 485 Communication Description
18
Controller TV70 Navigator User Manual / 87-900-956-01 (G) 165/182
RS 232/RS 485 Communication Description
Both the RS 232 and the RS 485 interfaces are available on the
connector J6. The communication protocol is the same (see the
structure below), but only the RS 485 manages the address field.
Therefore to enable the RS 485 is necessary to select the type of
communication as well as the device address by means of the
software.
Communication Format
ƒ
8 data bit
ƒ no parity
ƒ
1 stop bit
ƒ baud rate: 600/1200/2400/4800/9600 programmable
Communication Protocol
The communication protocol is a MASTER/SLAVE type where:
ƒ Host = MASTER
ƒ
Controller = SLAVE
The communication is performed in the following way:
1. the host (MASTER) send a M CRC to the controller
(SLAVE);
2. the controller answer with an CRC to the host.
The MESSAGE is a string with the following format:
<STX>+<ADDR>+<WIN>+<COM>+<DATA>+<ETX>+<CRC>
where: